Heating and humidifying system



April 18, 1939. s. M, ANDERSON ET AL 2,154,801

HEATING AND HUMIDIFYING SYSTEM Original Filed Feb. 5, 1936 I'Illlllll wil N m m 12 w w mv M v. 7

, WMT

Patented Apr. 18, 1939 HEATING AND HUMIDIFYING SYSTEM Samuel M. Anderson and Robert '1. Palmer,

Sharon, Mass., assignors to B. F. Sturtevant Company, Inc., Hyde Park,'Boston, Mala.

Original application February 5, 1936, Serial No. 62,470. Divided and this application June 9, 1938, Serial No. 212,742

7 Claims.

This invention relates to heating and humiditying systems and relates more particularly to heating and humidifying systems for passenger vehicles such as railroad passenger cars.

This application is a division of our application Serial No. 62,470, filed Feb. 5, 1936.

The benefits of humidifying heated air are well known but there are disadvantages which have in many cases prevented these benefits from being gained. For example, in a space having windows, it is impossible to maintain the desired relative humidity indoors when the outdoor temperature is low without the moisture in the humidified air condensing upon the inner surface of the window panes. This condensation takes place, of course, whenever the window pane is chilled by the outdoor air to a temperature below the dew point of the indoor air. This condensation upon the window panes is very undesirable especially in passenger vehicles such as railroad passenger cars where the passengers are accustomed to gaze at the passing scenery.

Attempts have been made in the past to solve this problem by lowering the indoor relative humidity conformably with the lowering of outdoor temperatures for the purpose of maintaining the dew point of the indoor air at all times below the temperature of the outdoor air. This has proved successful in preventing condensation but in order to accomplish this, it is necessary on cold days to reduce the indoor relative humidity far below that recognized as necessary for comfort. As a result of the fogging up of the window panes even when double sash windows are employed, the railroads for example, do not utilize to any extent humidified air in winter. This results in the absurd situation that the air is properly conditioned in railroad passenger cars in summer, but not in winter, despite the fact that the very dry heated air supplied to railroad passengers is very uncomfortable.

According to this invention, there is provided in combination with a system for supplying properly humidified air to a heated space, means for the heating of the window panes to such a temperature that they cannot be chilled by any outdoor temperature to the dew point of the properly humidified indoor air.

An object of this invention is to prevent the condensation of moisture from properly humidifled indoor air upon the surface of a window pane.

Another object of the invention is to maintain the window pane of an enclosure supplied with properly humidified air, at a temperature above the dew point of the humidified air.

Other objects of the invention will be apparent from the following description taken together with the drawing.

The invention will now be described with refer- Fig. 3 is a sectional view along the lines 33 of Fig. 2.

In the arrangement illustrated by Figs. 1 to 3 inclusive there is mounted in one end and in the roof zone of a railroad passenger car an air con- 15 ditioning compartment 20, containing the blowers 2|, the cooling coils 22 adapted to be supplied with a refrigerant in summer, the heating coils 23 adapted to be supplied with steam from the engine or other convenient source, and the humidifier spray nozzles 24 adapted to be supplied with water from a conveniently located source. Outside air is drawn in by the action of the blowers 2|, through the inlet 25, and recirculated air 25 is drawn in through the inlet 26. The hydrostat maintains the desired relative humidity by control through the valve SI of the sprays.

The conditioned air comprising heated and humidified air in winter is forced from the output side of the compartment 20 into the overhead longitudinal ducts 21. The ducts are provided with a plurality of spaced outlets 28 through which the conditioned air is supplied into the passenger space. 35

The passages 29 conduct a portion of the heated air leaving the heater coils 23 into the auxiliary overhead longitudinal ducts 30, which have at their bases at locations above the double sash windows of the car, the heated air outlets 3|, 40 which communicate as shown more clearly by Fig. 2 with the passages 32 above the window panes 33, the passages 34 between the panes 33, the passages 35 below the panes 33, and the outlets 33 into the passenger space of the car.

The heated air maintains the window panes at a relatively high temperature and prevents them from being chilled by the outdoor air to the dew point-of the humidified air discharged into the passenger space. By way of example, the air within the passenger space may be maintained at F. dry bulb temperature with a relative humidity of 40%, the resulting dew point being 49 F. The dry heated air supplied into the duct 30 at about F. will maintain the 55 window panes at a temperature above this dew point under'normal operating conditions.

In the accompanying drawing, only those details of car construction necessary for an understanding of the invention are shown. The drawing is purely diagrammatic as regards other details. For example, although the modern railroad passenger car has insulated air supply ducts and insulation at various locations, these details have been purposely omitted to avoid the showing of what is believed to be unnecessary detail.

While one embodiment of the invention has been described for the purpose of illustration, it should be understood that 'the invention is not limited to the exact apparatus and arrangement of apparatus described, since many departures may suggest themselves to those skilled in the'art without departure from the invention.

what is claimed is:

1. Air conditioning apparatus for a passenger vehicle having a double sash window, comprising an air conditioning unit, air heating and humidifying means in said unit, means for supplying humidified air from said unit directly into the passenger space of said vehicle, and means for passing dry, heated air from said unit between the panes of said window and then into said passenger space.

2. Air conditioning apparatus for a passenger vehicle having a double sash window, comprising an air conditioning unit, air heating and humidiiying means in said unit, a longitudinal duct overhead the passenger space of said vehicle, means for supplying humidified air from said unit into said duct, a second longitudinal duct, means for supplying dry, heated air from said unit into said second duct, and means for passing air from said second duct between the panes 01' said window and then into said passenger space. i

3. Air conditioning apparatus for a passenger vehicle having a double sash window, comprising an air conditioning unit, air heating and humidifying means in said unit, a longitudinal duct overhead the passenger space of said vehicle, means for supplying humidified air from said unit into said duct, a second longitudinal duct overhead said passenger space, means for supplying dry, heated air from said unit into said second duct, and means for passing air from said second duct between the panes of said window and then into said passenger space.

4. Air conditioning apparatus for a passenger vehicle having a double sash window. comprising an air conditioning unit, means for supplying air into said unit, a humidifier in said unit, an air heaterin said unit between said means and said humidifier, means for supplying heated and humidified air from said unit directly into the passenger space oi. said vehicle, means forming an air outlet passage from said unit between said heater and humidifier, and means for passing air from said passage between the panes of said window and then into said passenger space.

5. Air conditioning apparatus for a passenger vehicle having a double sash window, comprising an air conditioning unit, means for supplying air into said unit, a humidifier in said unit, an air heater in said unit between said means and said humidifier, a longitudinal distributing duct overhead the passenger space of said vehicle, for supplying heated and humidified air from said unit, means forming an air outlet passage from said unit between said heater and humidifier, and means for passing air from said passage between the panes of said window and then into said passenger space.

6. Air conditioning apparatus for a passenger vehicle having a double sash window, comprising an air conditioning unit, means for supplying air into said unit, a humidifier in said unit, an air heater in said unit between said means and said humidifier, a longitudinal distributing duct overhead the passenger space of said vehicle, for supplying heated and humidified air from said unit, means forming an air outlet passage from said unit between said heater and humidifier, a second longitudinal duct connected to said passage, and means for passing air from said second duct between the panes of said windows and then into said passenger space.

7. Air conditioning apparatus for a passenger vehicle having a double sash window, comprising an air conditioning unit, means for supplying air into said unit, a humidifier in said unit, an air heater in said unit between said means and said humidifier, a longitudinal distributing duct overhead the passenger space of said vehicle, for supplying heated and humidified air from said unit, means forming an air outlet passage from said unit between said heater and humidifier, a second longitudinal duct overhead saidpassenger space connected to said passage, and means for passing air from said second duct between the panes of said windows and then into said passenger space, at a point below said window.

- SAMUEL M. ANDERSON.

ROBERT T. PALMER. 

